Stabilizing vinylidene chloride



; .M' G VINYLIDENE CHLORIDE Michigan No Dra- Application April 24, 1937,Serial No. 138,131

(Jlaims.

This invention relates to methods of stabilizing vinylidene chloride,H2C=CC12, and to the improved composition thereby obtained.

When vinylidene chloride is exposed to the 5 action of air and light, agradual polymerization at least temporarily, against suchpolymerization,

so that it can be stored for a period of time following its preparation,and prior to its use in resin formation. It is, therefore, among theobjects of this invention to provide a process for inhibiting thepolymerization of vinylidene chloride. A further object of the inventionis to provide a relatively stable monomeric vinylidene chloride.Another'object of the invention is to provide a stabilized vinylidenechloride composition from which the stabilizing agent can be readilyremoved when desired.

We have discovered that vinylidene chloride can be stabilized againstthe action of air and light by incorporating therewith one or acombination of certain phenol derivatives, and, furbe readily separatedfrom the vinylidene chloride to render the same capable ofpolymerization.

The concentration of stabilizing agent to be employed in monomericvinylidene chloride may be varied, depending upon the length of time forwhich is desired to stabilize the compound and upon the efl'ectlvenessof the particular agent employed. We have found that an amount ofstabilizing agent equivalent to 10 per cent or less of the weight ofvinylidene chloride is ordinarily sumcient to maintain the vinylidenechloride in monomeric form over extended periods of time. When using theherein-described phenol derivatives as stabilizing agents, we havedetermined that between about 0.25 and about 1 per cent of such materialdissolved in or suspended in vinylidene chloride serves to preventpolymerizaiton for several weeks.

Among the substituted phenols which we employ arel'-hydroxy-2-cyclohexyl-phenol, N- (para-hydroxy-phenyl) -morpholine,hydroquinone-mono-benzyl ether, di-(para-hydroxyphenyl) -dimethylmethane, and methylene-dibeta-naphthol. Other phenol derivatives havingsimilar structures are also eifective as stabilizing agents forvinylidene chloride.

In a preferred method of carrying out our invention, a small amount ofone of the stabilizing agents mentioned above, suitably one perthermore, that these stabilizing agents can again cent, or less, basedon the weight of vinylidene chloride, is added to freshly distilledmonomeric vinylidene chloride, which may then be stored in a container.When it is desired to utilize the stabilized vinylidene chloride inpolymerization processes, the stabilizing agent may be readily andcompletely removed from the solution by distilling oil the lower boilingvinylidene chloride. The stabilizing agent is left in the still as aresidue after the distillation, and is adapted to be re-employed for thestabilization of further amounts of vinylidene chloride. The vinylidenechloride removed from the stabilizer by distillation is found topolymerize readily when exposed to light, air, elevated temperature, orother of the customary catalysts or accelerators for the polymerization.

The following example serves to illustrate the practice of ourinvention:

99.5 grams of vinylidene chloride were placed in each of 6 flasks. To 5of the samples there was added 0.5 gram of one of the new stabilizingagents, namely, l-hydroxy-2-cyclohexyl-phenol, N- (para-hydroxy-phenyl)-morpholine, hydroquinone-mono-benzyl ether, di-(para-hydroxy-phenyl)-dimethyl methane, and methylene-di-betanaphthol. The samples wereallowed to stand at room temperature and in contact with the air for aperiod of 2 weeks, at the end of which time no polymerization orodixation of the vinylidene chloride could be detected. In eachinstance, the vinylidene chloride distilled readily from the stabilizingagent and was thereafter readily polymerized. The untreated sample offreshly distiled vinylidene chloride was found to have polymerizedsubstantially completely after standing for 24 hours at room temperatureand. in contact with air. After having stood for only 5-6 hours, thisuntreated sample displayed evidence of polymerization and of oxidation,there being readily detected the odor of phosgene, one of the normaloxidation products of vinylidene chloride. Attempts to recover thevinylidene chloride from the polymerized untreated sample thereofresulted only in further oxidation and decomposition.

Other modes of applying the principle of our invention my be employedinstead of those explained, change being made as regards the materialsemployed, provided the step or steps or the products recited in thefollowing claims be thereby carried out or obtained.

We therefore particularly point out and distinctly claim as ourinvention:-

1. vinylidene chloride containing up to 10 per cent by weight of acompound selected from the group consisting of'1'-hydroxy-2-cyclohezwlphenol, N para-hydroxy-phenyl) -morpholine,hydroquinone-mono-benzyl ether, di-(para-hydroxy-phenyl) -dimethylmethane, and methylen-di-beta-naphthol.

2. Vinylidene chloride stabilized with a compound selected from thegroup consisting of 1- hydrpxy-2-cyclo-hexyl-phenol, N (para.hydroxy- 10phenyl) -morpholine, hydroquinone-mono-benzyl ether, di-(para-hydroxy-phenyl) -dimethyl methane, andmethylene di-beta-naphthol.

3. Vinylidene chloride stabilized with hydroquinone-mono-benzyl ether.

4. Vinylidene chloride stabilized with di-(parahydroxy-phenyl) -dimethylmethane.

5. Vinylidene chloride stabilized with methylene-di-beta-naphthol.

EDGAR c. BR I'ITON.

WALTER J. LE FEVRE. 10

